Wash, clean and quarter the peppers. Preheat the oven grill to the highest setting. Roast the peppers on the top rack under the grill until the skin blisters.
Take the peppers out of the oven and cover with a wet kitchen towel until they are cold. Peel off the skin.
Mix a marinade from the olive oil, balsamic vinegar, salt and pepper. Cut the peppers into thin strips and soak in the marinade, preferably overnight. Season again with salt, pepper and aceto.
Chop the parsley very finely and mix with the peppers. Serve with white bread.